Brushless Hub Motor power draw

sp00ns

Just Joined
Nov 20, 2020
4
0
Hi all
first poster

I have a voilamart rear hub motor. I've read in a few places that even when idle or when coasting, the hub motor will draw power from the battery, but I can't seem to get a definitive answer if that is actually the case.

for example, if I ride up a big hill, then ride down the other side, will the spinning wheel draw lots of current from the battery? or if I turn on then leave standing for an hour, will the motor draw power and generate heat due to the resistance of the non moving wheel? or am I laughably wrong about the whole thing and power ONLY goes in when the (lets keep it simple) throttle is opened?

Any light shed gratefully accepted
 

sp00ns

Just Joined
Nov 20, 2020
4
0
750W Rear Wheel with PAS LCD Meter. 36V. I remember it's brushless.

no other info remains on ebay, bought it a few years back.

If we can't pin down specifically on the model, can we talk in general terms? it sounds like it's not a straightforward NO or YES
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,985
Basildon
Without seeing which motor it is, I can't say because direct drive and geared motors behave completely differently.
 

sp00ns

Just Joined
Nov 20, 2020
4
0
ok, after a lifetime of looking i've found it. amazingly it's still being sold years later.

brushless gearless

so, back to my original Q, if freewheeling downhill, or stood still powered on, will this type of hub motor (brushless gearless) draw power? if so, how much? will freewheeling very fast down a steep hill draw so much the bms cuts in? because i've had the bms cut out at the end of a hill a couple of times...
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,985
Basildon
The answer is no, though your controller will use about 4W.

The motor will be generating when you go fast downhill, so if your controller has regen, it could be overheating the BMS.